HomeSupportCan the Nonlinear Curve Fit.vi Be Modified to Handle the Input f(x) Scaled down by 1E-9?

Can the Nonlinear Curve Fit.vi Be Modified to Handle the Input f(x) Scaled down by 1E-9?

Updated Jun 15, 2018

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Software

LabVIEW 2016 Full

Operating System

Windows

Issue Details

I have been using the Levenburg-Marquardt Alogorithm example in LabVIEW called "Sum of 3 Gaussians with offset fit" to develop my curve fit application. When I scale the data f(x) by a factor of 1E-9 the Non Linear Curve Fit.vi is no longer able to properly converge and fails to plot the correct curve fit line as shown here. Can this example program be modified to handle data scaled by this factor?

Solution

By default the Non Linear Curve Fit.vi is set to have a tolerance of 1E-8. If you adjust the tolerance to 1E-12 on the block diagram as shown below it will properly converge data scaled by a factor of 1E-9. Now you can see the curve fit line is applied correctly.